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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /samples/bpf/tracex5_kern.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | samples/bpf/tracex5_kern.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/samples/bpf/tracex5_kern.c b/samples/bpf/tracex5_kern.c new file mode 100644 index 000000000..64a1f7550 --- /dev/null +++ b/samples/bpf/tracex5_kern.c @@ -0,0 +1,93 @@ +/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ +#include <linux/ptrace.h> +#include <linux/version.h> +#include <uapi/linux/bpf.h> +#include <uapi/linux/seccomp.h> +#include <uapi/linux/unistd.h> +#include "syscall_nrs.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +#define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F + +struct { + __uint(type, BPF_MAP_TYPE_PROG_ARRAY); + __uint(key_size, sizeof(u32)); + __uint(value_size, sizeof(u32)); +#ifdef __mips__ + __uint(max_entries, 6000); /* MIPS n64 syscalls start at 5000 */ +#else + __uint(max_entries, 1024); +#endif +} progs SEC(".maps"); + +SEC("kprobe/__seccomp_filter") +int bpf_prog1(struct pt_regs *ctx) +{ + int sc_nr = (int)PT_REGS_PARM1(ctx); + + /* dispatch into next BPF program depending on syscall number */ + bpf_tail_call(ctx, &progs, sc_nr); + + /* fall through -> unknown syscall */ + if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) { + char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n"; + bpf_trace_printk(fmt, sizeof(fmt), sc_nr); + } + return 0; +} + +/* we jump here when syscall number == __NR_write */ +PROG(SYS__NR_write)(struct pt_regs *ctx) +{ + struct seccomp_data sd; + + bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx)); + if (sd.args[2] == 512) { + char fmt[] = "write(fd=%d, buf=%p, size=%d)\n"; + bpf_trace_printk(fmt, sizeof(fmt), + sd.args[0], sd.args[1], sd.args[2]); + } + return 0; +} + +PROG(SYS__NR_read)(struct pt_regs *ctx) +{ + struct seccomp_data sd; + + bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx)); + if (sd.args[2] > 128 && sd.args[2] <= 1024) { + char fmt[] = "read(fd=%d, buf=%p, size=%d)\n"; + bpf_trace_printk(fmt, sizeof(fmt), + sd.args[0], sd.args[1], sd.args[2]); + } + return 0; +} + +#ifdef __NR_mmap2 +PROG(SYS__NR_mmap2)(struct pt_regs *ctx) +{ + char fmt[] = "mmap2\n"; + + bpf_trace_printk(fmt, sizeof(fmt)); + return 0; +} +#endif + +#ifdef __NR_mmap +PROG(SYS__NR_mmap)(struct pt_regs *ctx) +{ + char fmt[] = "mmap\n"; + + bpf_trace_printk(fmt, sizeof(fmt)); + return 0; +} +#endif + +char _license[] SEC("license") = "GPL"; +u32 _version SEC("version") = LINUX_VERSION_CODE; |